Ok... I have been trying to figure this mess out, and I think I got it, except for one last (potentially very big) problem.
I have had iTunes Match for almost a year. I have a copy of every song I own on my Mac. In iTunes, if I show the columns "Kind" and "iCloud Status", this is what I see:
iCloud Status -- Kind
------------------------
Matched -- Matched AAC audio file
Uploaded -- MPEG audio file
Purchased -- Purchased AAC audio file
That all makes perfect sense to me, as a 1-to-1 mapping between "iCloud Status" and "Kind". When I delete the song from iTunes, I can download exactly the same "Kind" as shown here.
BUT... now I have the free Apple Music subscription, and this is what I see on songs I have Made Available Offline from Apple Music Playlists:
iCloud Status -- Kind
------------------------
Apple Music -- Matched AAC audio file
Apple Music -- MPEG audio file
Apple Music -- Purchased AAC audio file
Apple Music -- Apple Music ACC audio file
The last one is DRM protected, which I understand. But I don't understand why the first three are getting set to Status = Apple Music. I have non-DRM copies of them that I own already!
It seems like Apple Music was unable to find the matching song from iTunes Match, and changed the "iCloud Status" to Apple Music (Protected by DRM). So if I start downloading a lot of playlist songs, my library will slowly be converted to Apple Music, at least according to Apple Music servers. If I ever accidentally delete these songs, I can only re-download the DRM version that will disappear when my subscription ends, even though I had them on iTunes Match for a year already.
Does anyone see similar behavior? Any idea what is going on? Am I looking at this the wrong way? They aren't adding DRM to my files, but they are setting the "Status" to Apple Music which means I can never download a DRM-free version of that song in the future, even though I had it before.
Any ideas? Help? Thanks everyone!